<?xml version="1.0" encoding="utf-8" ?>
<!--Created with Liquid XML Studio - Education Edition 7.1.1.1206 (http://www.liquid-technologies.com)-->
<xs:schema xmlns="http://his.cuahsi.org/schema/extentsions" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://his.cuahsi.org/schema/extentsions" version="1" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="variableExtension">
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="0" maxOccurs="1" name="speciation" type="xs:string" />
        <xs:element minOccurs="0" maxOccurs="unbounded" name="noDataValueExtended" type="NoDataValueTypes" />
        <xs:element minOccurs="0" maxOccurs="unbounded" name="variableProperty" type="PropertyType" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:complexType name="NoDataValueTypes">
    <xs:sequence>
      <xs:element name="DataValue" type="xs:float" />
      <xs:element name="brief" type="xs:string" />
      <xs:element name="detailed" type="xs:string" />
    </xs:sequence>
  </xs:complexType>
  <xs:complexType name="PropertyType">
    <xs:simpleContent>
      <xs:extension base="xs:string">
        <xs:attribute name="type" use="optional" />
        <xs:attribute name="name" use="required" />
        <xs:attribute name="uri" use="optional" />
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
  <xs:element name="seriesExtension">
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="0" maxOccurs="unbounded" name="seriesProperty" type="PropertyType" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:element name="siteExtension">
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="0" maxOccurs="unbounded" name="siteType" type="xs:string" />
        <xs:element minOccurs="0" maxOccurs="1" name="hucCode" type="xs:token" />
        <xs:element minOccurs="0" maxOccurs="unbounded" name="siteProperty" type="PropertyType" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>